[PATCH 06/13] x86, dax, libnvdimm: move wb_cache_pmem() to libnvdimm

From: Dan Williams
Date: Thu Jan 19 2017 - 22:54:58 EST


With all calls to this routine re-directed through the pmem driver, we
can kill the pmem api indirection. arch_wb_cache_pmem() is now
optionally supplied by an arch specific extension to libnvdimm. Same as
before, pmem flushing is only defined for x86_64, but it is
straightforward to add other archs in the future.

Cc: <x86@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/x86/include/asm/pmem.h | 20 --------------------
drivers/nvdimm/Makefile | 1 +
drivers/nvdimm/pmem.c | 4 ++--
drivers/nvdimm/pmem.h | 9 +++++++++
drivers/nvdimm/x86.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/pmem.h | 19 -------------------
tools/testing/nvdimm/Kbuild | 1 +
7 files changed, 49 insertions(+), 41 deletions(-)
create mode 100644 drivers/nvdimm/x86.c

diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
index ab4983df7bff..4759a179aa52 100644
--- a/arch/x86/include/asm/pmem.h
+++ b/arch/x86/include/asm/pmem.h
@@ -44,26 +44,6 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
BUG();
}

-/**
- * arch_wb_cache_pmem - write back a cache range with CLWB
- * @vaddr: virtual start address
- * @size: number of bytes to write back
- *
- * Write back a cache range using the CLWB (cache line write back)
- * instruction.
- */
-static inline void arch_wb_cache_pmem(void *addr, size_t size)
-{
- u16 x86_clflush_size = boot_cpu_data.x86_clflush_size;
- unsigned long clflush_mask = x86_clflush_size - 1;
- void *vend = addr + size;
- void *p;
-
- for (p = (void *)((unsigned long)addr & ~clflush_mask);
- p < vend; p += x86_clflush_size)
- clwb(p);
-}
-
static inline void arch_invalidate_pmem(void *addr, size_t size)
{
clflush_cache_range(addr, size);
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 909554c3f955..9eafb1dd2876 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -24,3 +24,4 @@ libnvdimm-$(CONFIG_ND_CLAIM) += claim.o
libnvdimm-$(CONFIG_BTT) += btt_devs.o
libnvdimm-$(CONFIG_NVDIMM_PFN) += pfn_devs.o
libnvdimm-$(CONFIG_NVDIMM_DAX) += dax_devs.o
+libnvdimm-$(CONFIG_X86_64) += x86.o
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 68fc7599a053..838241bb31d1 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -222,14 +222,14 @@ static size_t pmem_copy_from_iter(void *addr, size_t bytes,
{
size_t rc = copy_from_iter_nocache(addr, bytes, i);

- wb_cache_pmem(addr, bytes);
+ arch_wb_cache_pmem(addr, bytes);
return rc;
}

static const struct dax_operations pmem_dax_ops = {
.direct_access = pmem_direct_access,
.copy_from_iter = pmem_copy_from_iter,
- .flush = wb_cache_pmem,
+ .flush = arch_wb_cache_pmem,
};

static const struct block_device_operations pmem_fops = {
diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h
index b4ee4f71b4a1..4faacff434ff 100644
--- a/drivers/nvdimm/pmem.h
+++ b/drivers/nvdimm/pmem.h
@@ -7,6 +7,15 @@

long pmem_direct_access(struct block_device *bdev, sector_t sector,
void **kaddr, pfn_t *pfn, long size);
+
+#ifdef CONFIG_ARCH_HAS_PMEM_API
+void arch_wb_cache_pmem(void *addr, size_t size);
+#else
+static inline void arch_wb_cache_pmem(void *addr, size_t size)
+{
+}
+#endif
+
/* this definition is in it's own header for tools/testing/nvdimm to consume */
struct pmem_device {
/* One contiguous memory region per device */
diff --git a/drivers/nvdimm/x86.c b/drivers/nvdimm/x86.c
new file mode 100644
index 000000000000..79d7267da4d2
--- /dev/null
+++ b/drivers/nvdimm/x86.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright(c) 2015 - 2017 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include <asm/cacheflush.h>
+#include <asm/cpufeature.h>
+#include <asm/special_insns.h>
+
+/**
+ * arch_wb_cache_pmem - write back a cache range with CLWB
+ * @vaddr: virtual start address
+ * @size: number of bytes to write back
+ *
+ * Write back a cache range using the CLWB (cache line write back)
+ * instruction.
+ */
+void arch_wb_cache_pmem(void *addr, size_t size)
+{
+ u16 x86_clflush_size = boot_cpu_data.x86_clflush_size;
+ unsigned long clflush_mask = x86_clflush_size - 1;
+ void *vend = addr + size;
+ void *p;
+
+ for (p = (void *)((unsigned long)addr & ~clflush_mask);
+ p < vend; p += x86_clflush_size)
+ clwb(p);
+}
+EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index 772bd02a5b52..33ae761f010a 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -31,11 +31,6 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
BUG();
}

-static inline void arch_wb_cache_pmem(void *addr, size_t size)
-{
- BUG();
-}
-
static inline void arch_invalidate_pmem(void *addr, size_t size)
{
BUG();
@@ -80,18 +75,4 @@ static inline void invalidate_pmem(void *addr, size_t size)
if (arch_has_pmem_api())
arch_invalidate_pmem(addr, size);
}
-
-/**
- * wb_cache_pmem - write back processor cache for PMEM memory range
- * @addr: virtual start address
- * @size: number of bytes to write back
- *
- * Write back the processor cache range starting at 'addr' for 'size' bytes.
- * See blkdev_issue_flush() note for memcpy_to_pmem().
- */
-static inline void wb_cache_pmem(void *addr, size_t size)
-{
- if (arch_has_pmem_api())
- arch_wb_cache_pmem(addr, size);
-}
#endif /* __PMEM_H__ */
diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild
index 405212be044a..7488dfa1309a 100644
--- a/tools/testing/nvdimm/Kbuild
+++ b/tools/testing/nvdimm/Kbuild
@@ -66,6 +66,7 @@ libnvdimm-$(CONFIG_ND_CLAIM) += $(NVDIMM_SRC)/claim.o
libnvdimm-$(CONFIG_BTT) += $(NVDIMM_SRC)/btt_devs.o
libnvdimm-$(CONFIG_NVDIMM_PFN) += $(NVDIMM_SRC)/pfn_devs.o
libnvdimm-$(CONFIG_NVDIMM_DAX) += $(NVDIMM_SRC)/dax_devs.o
+libnvdimm-$(CONFIG_X86_64) += $(NVDIMM_SRC)/x86.o
libnvdimm-y += config_check.o

obj-m += test/